Implementation of fuzzy logic control algorithm for temperature control in robusta rotary dryer coffee bean dryer

Area of Science:

• Agricultural Engineering
• Food Science and Technology
• Control Systems

Background:

• Indonesia ranks third globally in coffee bean supply, necessitating quality maintenance for market competitiveness.
• Maintaining optimal moisture content in green coffee beans is crucial for preserving quality.
• Traditional drying methods face limitations due to weather dependency and prolonged drying times.

Purpose of the Study:

• To design and evaluate an innovative coffee bean dryer utilizing fuzzy logic control.
• To overcome the limitations of traditional drying methods in terms of time and weather dependency.
• To ensure green coffee beans achieve the standard moisture content of 12%.

Main Methods:

• Implementation of Mamdani's fuzzy logic control algorithm for temperature regulation.
• Utilizing input and delta errors with a percentage valve opening output for precise control.
• Incorporating coffee bean mass variation into drying time estimations.

Main Results:

• Achieved target moisture content of 12%, adhering to Indonesian National Standards (SNI).
• Attained a consistent drying rate of 0.00015%/s per kilogram of coffee beans.
• Maintained a stable drying temperature of 50°C with high efficiency.

Conclusions:

• The fuzzy logic-based dryer successfully dried Robusta coffee beans to 12% moisture content within 90-195 minutes.
• The system demonstrated effective drying for capacities ranging from 1kg to 10kg at 50°C.
• This technology offers a viable solution for consistent, high-quality coffee bean drying in post-harvest processing.